Power takeoff centrifugal pump with ring and pinion drive

ABSTRACT

In combination, a centrifugal pump means having an enclosed pumping chamber with an inlet and an outlet, along with an impeller journaled for rotation within the chamber and a drive shaft arranged to provide rotational energy to the impeller; and a power-transmission means coupled to the centrifugal pump for driving the drive shaft, the power-transmission means having an input coupling for direct mounting onto a tractor power takeoff shaft with the input energy being coupled through a ring and pinion to the drive shaft for the pump. The power-transmission means comprises a ring and pinion system with a drive hub member which forms a portion of the input coupling being secured through suitable cushioning means, to the ring gear, the ring gear being fabricated from relatively durable material, and with the pinion gear being fabricated from relatively soft material such as nylon or the like. The pinion is mounted directly on the centrifugal pump drive shaft and provides its rotational energy. The rotating ring gear is coupled to the drive hub in such a way that limited relative arcuate motion may occur between these components within the power-transmission housing, the drive hub having a plurality of arcuate resilient pad-receiving slots formed therein, the ring gear having an outer cylindrical surface with a plurality of lugs secured thereto which are arranged to fit within the arcuate slots formed in the drive hub. The resilient pads have tip portions with a relatively reduced cross section, and a central body or shank portion with an enlarged cross section, these pads extending arcuately laterally on either side of the lugs on the ring gear and thereby adapted to permit limited relative arcuate motion between the drive hub and the ring gear in response to torque loading of the drive shaft.

United States Patent (72] Inventors Harry J. Sadler Anurney()rrin M. Haugen St. Paul; Ramon Pareja. Minneapolis, both of, Minn. [2|] Appl. No. 1,794 ABSTRACT: In combination, a centrifugal pump means hav- [22] Filed Jan. 9, 1970 ing an enclosed pumping chamber with an inlet and an outlet, [45] Patented Aug. 3, 1971 along with an impeller journaled for rotation within the [73] Assignee Hypro,1nc. chamber and a drive shaft arranged to provide rotational ener- St. Paul. Minn. gy to the impeller; and a power-transmission means coupled to the centrifugal pump for driving the drive shaft, the powertransmission means having an input coupling for direct mounting onto a tractor power takeofi' shaft with the input energy being coupled through a ring and pinion to the drive shaft for 54 POWERTAKEOFFCENTRIFUGAL PUMP WITH the pump. The power-transmission means comprises a ring mc AND PINION DRIVE and pinion system with a drive hub member which forms a 8 Chins; Drawing Figs portion of the input coupling being secured through suitable 2 cushioning means, to the ring gear, the ring gear being [5 US. Cl. 415/122, fabricated f relatively durable material, and with the 5 74/41 417/2311 415/204 pinion gear being fabricated from relatively soft material such l] lnt. Cl "F2361 as nylon or the like. The pinion is mounted directly on he trifugal pump drive shaft and provides its rotational energy. [50] Field of Search 415/122, The rotating ring gear isgcoupled to the drive hub in such a 204; 417/124 2343 74mm way that limited relative arcuate motion may occur between [56] References Cited these components within the power-transmission housing the drive hub having a plurality of arcuate resilient pad-receiving UNITED STATES PATENTS slots formed therein, the ring gear having an outer cylindrical 2,672,097 3/1954 Pfingsten 415/122 surface with a plurality of lugs secured thereto which are ar- 2,695,131 1 1/1954 Price 415/122 ranged to fit within the arcuate slots formed in the drive hub. 3,145,912 8/1964 Weis 415/122 The resilient pads have tip portions with a relatively reduced 3,174,352 3/1965 Jekat 74/411 cross section, and a central body or shank portion with an en- FOREIGN PATENTS larged cross section, these pads extending arcuately laterally 1,004,929 3/1957 Germany 415/122 f P "5 the and hereby 902,496 8/1962 Great Britain 415/12 o permit limit ed relative arcuate motion between the drive hub and the ring gear in response to torque loading of the Primary Examiner-Henry F. Raduazo d i h f T as 38 IO 39 42 4o 43 46 45 '3 3o ig E. i i. I l4 36 -21 J 20 .1 24 l as I a Patented Aug. 3, 1971 2 Sheets-Sheet F;

INVENTORS HARRY J. SADLER RAMON FARE/A ATTORNEY POWER TAKEOFF CENTRIFUGAL PUMP WITH RING AND PINION DRIVE The present invention relates generally to a tractor power takeoff mounted centrifugal pump, and more particularly to the combination of such a pump with a ring and pinion drive system adapted to accommodate the mounting of the pump within the conventional volume traditionally available around the power takeoff shaft of farm tractors.

Power takeoff shafts of farm tractors are frequently employed for the pumping of liquids for a variety of reasons. These pumps are normally driven with power from the power takeoff shaft of the ordinary farm tractor, and in the past these units have generally been so large that it has been impossible to provide for mounting within the shield area. For convenience and safety in mounting, it is necessary that the pump and the drive system for the pump be compact so as to permit mounting and retention in the area within the confines of the shield normally employed for this purpose. Shields employed at the present time are arranged to enclose a cavity which extends a distance of approximately 4 inches from the spline center to the shield base, and any unit to be received within this area must, of course, have a corresponding diameter or size. With conventional gearing, it has been considered im possible to provide a suitable drive mechanism using normal materials of construction. Therefore, it has been customary to mount the unit in such a manner that it is ordinarily attached in an area remote from the shield base of the power takeoff shield.

The apparatus of the present invention has been designed to provide a rugged pump with a small diameter housing which easily fits under the power takeoff shield of conventional farm tractors. The system employs a ring and pinion gear drive, the output of which drives a high capacity centrifugal pump. The ring and pinion drive, while rugged, is also provided with sacrificial gearing in order to accommodate problems which may arise due to locked rotor situations which can occur in the normal use of this type of pump.

Therefore, it is a principal object of the present invention to provide an improved rugged centrifugal pump having a ring and pinion gear drive capable of being received within the confines of the shielded area provided for the power takeoff shaft of a farm tractor.

It is a further object of the present invention to provide an improved rugged centrifugal pump having high capacity and rugged features, but having sacrificial gearing for accommodating locked rotor problems which may occur during the normal operation of pumps of this type.

It is yet a further object of the present invention to provide an improved centrifugal pump unit having a power transmission means coupled directly to the centrifugal pump, the power transmission utilizing a ring and pinion gear system having a ring gear mounted for limited relative arcuate motion within the power transmission housing in response to torque loading of the drive shaft ofthe centrifugal pump.

Other and further objects of the present invention will become apparent to those skilled in the art upon a study of the following specification, appended claims, and accompanying drawings, wherein:

FIG. 1 is a vertical sectional view, taken along and through the diameter of the improved centrifugal pump of the present invention, and showing portions of the impeller housing in elevation;

FIG. 2 is a vertical sectional view, taken along the line and in the direction of the arrows 2-2 of FIG. 1;

FIG. 3 is a vertical sectional view, taken along the line and in the direction ofthe arrows 3-3 of FIG. 1; and

FIG. 4 is a detail perspective view of the resilient pad or cushion bumper having a desirable configuration for use in the coupling of the drive hub to the ring gear.

In accordance with the preferred modification of the present invention, the combined centrifugal pump and drive assembly generally designated includes a pump portion 11 along with the power transmission portion 12. The pump portion 11 includes a pump-casing segment 13 along with a head 14, thus providing a pumping chamber as at 16, the chamber being provided with an inlet as at 17 and an outlet as at 18. The inlet and outlet are threaded for receiving suitable conduits in operative relationship therewith. The pump portion 11 is provided with a drive shaft 20 having a key 21 coupling the shaft to the impeller 22, nut 23 along with washer 24 being utilized to retain the impeller 22 on the shaft 20 and in sealed relationship therewith. The impeller 22 is provided with conventional blades and the like such as are shown at 26, the operation of this pump being conventional and therefore not unusual. A mechanical seal 28 is employed to prevent leakage of the fluids being pumped to the atmosphere, or to the drive housing 12. Conventional capscrews or the like as shown at 29 are preferably employed to retain the head 14 on the housing portion 13, conventional O-rings such as are shown at 30 being utilized as gaskets to seal the pumping chamber 16 from the atmosphere. For accommodating drainage of the pumping chamber 16, a pair of drain plugs are provided, one being shown at 31, these being conveniently removed when it is desired to drain the system.

Attention is now directed to the power transmission means or portion shown at 12, the power transmission means being coupled to the body portion 13 and including the gear housing disposed around the drive or driver hub 36 and the ring gear 37. Shoulder bolts such as are shown at 38,38 are employed to couple the driver hub 36 and ring gear 37 in desired relative disposition, one to another. Driver hub 36 is provided with a setscrew such as at 40 for suitably locking the mechanism onto the power takeoff shaft ofthe driving tractor, when appropriate.

Driver hub 36 is provided with a counterbore area as at 42 for receiving the main bearing assemblies 43,43, these bearings being, in turn, received on the main bearing shaft 44. A setscrew such as is shown at 45 is utilized to suitably lock or mount the main bearing shaft 44 to the housing 13. A retainer ring is shown at 46, this ring being utilized to properly and appropriately retain the driver hub 36 and ring gear 37 onto bearing shaft 44.

Attention is now directed to FIG. 2 of the drawings, with continued attention being directed to FIG. 1, for a discussion of the arrangement of the pinion gear and impeller shaft 20 assembly. Pinion is secured to shaft 20 by means of bolt 51, shaft 20 being provided with a pair of flats such as are shown at 52 and 53 for providing locking rotation between pinion 50 and shaft 20. While other materials can be utilized, it is preferred that pinion 50 be fabricated from molded nylon, or molded polytetrafluoroethylene, this material being generally softer and thus providing a sacrificial component should a locked rotor condition or other trouble occur during operation of the unit. The combined pair of flat areas as shown at 52 and 53 along with a molded nylon pinion has been found desirable and useful. As indicated in FIG. 1, shaft 20 is provided with appropriate double race ball bearing means at 55 to control the rotation of this member within the confines of housing 13. Also, a bearing retainer ring is deemed appropriate, such as is shown at 56. Obviously, other bearing means such as needle bearings may be employed, if desired.

Attention is now directed to FIGS. 3 and 4 of the drawings, with continued attention being directed to FIG. 1, for a discussion of the details of controlled arcuate rotation of the driver hub 36 relative to the ring gear 37. Specifically, a resilient pad such as the cushion bumper 60, shown in FIG. 4, is interposed in the area so as to accommodate shifting rotation, when required. Shoulder bolts 38 are adapted to slidably fit the bore 61 formed in the bumper 60, these shoulder bolts then having a threaded shank portion as at 62 for the threaded bore formed in the ring gear 37. Thus, upon experiencing excessive shock loading, the pad permits relative rotation between hub 36 and ring gear 37 so as to avoid breakage of any of the components of the drive transmission assembly.

RESILIENT PAD DESIGN The cushion bumpers 60 are preferably made from a relatively firm rubber, preferably of about 60-70 durometer, although other materials may be utilized for accommodating unusual operation. This will provide sufficient resiliency and sufficient firmness to protect the mechanism against damage due to sudden shock loading, and will also accommodate a modest amount of relative arcuate rotation between driver hub 36 and ring gear 37. ln order to assist the mechanism in accommodating this relative arcuate rotation while maintaining alignment, the main bearings 43 and shaft 44 are useful for appropriately guiding the axis of driver hub 36.

With particular attention being continued to FIG. 4, it will be seen that the resilient pad or cushion bumper 60 has a relatively enlarged central shank portion along with tapered ends, the ends extending diametrically outwardly from the bore 61. This configuration is utilized in order to accommodate arcuate shifting, without setting up or establishing excessive strains in the coupling mechanism, including the shoulder bolts 38 and the threaded bores formed in the ring gear 37 for accommodatingthese bolts.

GENERAL DESIGN CONSXDERATIONS No unusual materials of construction are required, it being possible to obtain good results with commercially available gearing and the like. Ring gear 37 may be prepared from diecast zinc, it being appreciated that other suitable durable material such as cast aluminum may be employed as well. it is, of course, desired that the material forming this component be generally more durable than that of the pinion 50. The impeller, if use with unusual fluids or liquids is deemed possible, is preferably fabricated from molded plastic or the like, impellers ofthis type being, of course, commercially available.

It is noted that the flats formed in the shaft 20 at 52 and 53 comprise approximately 50 percent of the total periphery of the shaft. This feature ha been found desirable in providing maximum strength in the arrangement of the sacrificial pinion gear, and is superior to a conventional key system.

The generally triangular configuration ofthe pads 60 permit a gradual increase in the torque resisting arcuate motion between the driver hub 36 and the ring gear 37. Thus, as the degree of arcuate shifting increases, the resistance toward further relative shifting also increases. A study of FIG. I of the drawings indicates that the driver hub 36 has an annular recessed flange area which is generally concentric with the internal circumference of the inwardly extending flange of the ring gear 37. This recessed flange area provides a shoulder 39 which forms a guiding surface for controlling the arcuate shifting between driver hub 36 and ring gear 37.

Dust shield 63 is preferably utilized to seal the interior of housing 35 from the atmosphere. it being appreciated that no unusual requirements exist for this component of the system.

In some instances, it may be desirable to utilize a modified form of input energy for the direct coupling to the power takeoff shaft, and accordingly suitable belting or chain drives may be employed.

It will be appreciated that the details of the structure shown herein are for purposes of illustration only and those skilled in the art may substitute certain equivalent features for those shown.

What we claim is:

1. In combination:

a centrifugal pump means having an enclosed pumping chamber with an inlet and an outlet, an impeller journaled for rotation within said chamber and a drive shaft arranged to provide rotational energy to said impeller; and a power transmission means coupled to said centrifugal pump means for driving said drive shaft, said power transmission means being mounted within a housing and having an input coupling for direct mounting onto a tractor power takeoff shaft with the input thereof being coupled to said drive shaft;

a. said power transmission means comprising a ring and pinion gear system with driver hub means secured to said input coupling, said ring and pinion gear system including:

b. a ring gear means with axially inwardly directed teeth secured to said driver hub and arranged for limited relative arcuate rotation with said driver hub within said power transmission housing, said ring gear means having a plurality of radially outwardly disposed equally arcuately spaced mounting means thereon for coupling to said driver hub;

. a plurality of radially outwardly disposed equally arcuately spaced mounting means formed in said driver hub for accommodating coupling of said ring gear mounting means to said driver hub;

cl. a pinion gear in mesh with said axially inwardly directed teeth and fast on said drive shaft, said pinion gear being fabricated from a material less durable than said ring gear and being sacrificial;

e. a plurality of bores in said hub means and a plurality of coupling members having central shank portions and one being disposed at each arcuately spaced mounting means location; and

. resilient pads circumscribing said central shank portions at each arcuately spaced mounting means location, and adapted to be confined within each said bore, said resilient pads having a body with a solid volume less than said bore and being adapted to permit limited relative arcuate motion between said driver hub and said ring gear in response to torque loading.

2. The centrifugal pump means as defined in claim 1 being particularly characterized in that said bores are formed within said driver hub and a threaded bore is formed within said ring gear, and wherein shoulder bolts with smooth central shank portions couple said ring gear to said driver hub.

3. The centrifugal pump means as defined in claim 1 being particularly characterized in that said arcuately spaced mounting means are disposed at 90intervals adjacent the periphery of said ring gear and driver hub.

4. The centrifugal pump means as defined in claim 1 being particularly characterized in that said resilient pads are formed of rubber having a hardness ranging from between about 60 durometer and durometer.

5. The centrifugal pump means as defined in claim 1 being particularly characterized in that said resilient pads have a generally triangular configuration with a finite thickness and with a central bore extending therethrough, and with laterally converging sides extending from said bore.

6. The centrifugal pump means as defined in claim 5 being particularly characterized in tha said resilient pads are fabricated from rubber and have a hardness ranging from between about 60 durometer and 80 durometer.

7. The centrifugal pump means as defined in claim 1 being particularly characterized in that said pinion gear is secured to said drive shaft along two flats formed along said shaft and arranged in oppositely disposed relationship thereon, the flats comprising approximately 50 percent of the total periphery of said drive shaft.

8. In combination:

a centrifugal pump means having an enclosed pumping chamber with an inlet and an outlet, an impeller journaled for rotation within said chamber and a drive shaft arranged to provide rotational energy to said impeller; and a power transmission means coupled to said centrifugal pump means for driving said drive shaft, said powertransmission means being mounted within a housing and having an input arranged for coupling to a source of rotational energy with the rotational energy being coupled to said drive shaft;

a. said power transmission means comprising a ring and pinion gear system with driver hub means secured to said input coupling, said ring and pinion gear system including:

b a ring gear means with axially inwardly directed teeth a plurality of radially outwardly disposed equally arcuately spaced mounting means formed in said driver hub for accommodating coupling of said ring gear mounting means to said driver hub;

. a pinion gear in mesh with said axially inwardly directed teeth and fast on said drive shaft, said pinion gear being fabricated from a material less durable than said ring gear and being sacrificial;

. a plurality of bores and a plurality of coupling members having central shank portions and being disposed at each arcuately spaced mounting means location; and

. a resilient means disposed at each arcuately spaced mounting means location, and adapted to be confined within each said bore, said resilient means being adapted to forcibly accommodate limited relative shifting between said driver hub and said ring gear in response to torque loading. 

1. In combination: a centrifugal pump means having an enclosed pumping chamber with an inlet and an outlet, an impeller journaled for rotation within said chamber and a drive shaft arranged to provide rotational energy to said impeller; and a power transmission means coupled to said centrifugal pump means for driving said drive shaft, said power transmission means being mounted within a housing and having an input coupling for direct mounting onto a tractor power takeoff shaft with the input thereof being coupled to said drive shaft; a. said power transmission means comprising a ring and pinion gear system with driver hub means secured to said input coupling, said ring and pinion gear system including: b. a ring gear means with axially inwardly directed teeth secured to said driver hub and arranged for limited relative arcuate rotation with said driver hub within said power transmission housing, said ring gear means having a plurality of radially outwardly disposed equally arcuately spaced mounting means thereon for coupling to said driver hub; c. a plurality of radially outwardly disposed equally arcuately spaced mounting means formed in said driver hub for accommodating coupling of said ring gear mounting means to said driver hub; d. a pinion gear in mesh with said axially inwardly directed teeth and fast on said drive shaft, said pinion gear being fabricated from a material less durable than said ring gear and being sacrificial; e. a plurality of bores in said hub means and a plurality of coupling members having central shank portions and one being disposed at each arcuately spaced mounting means location; and f. resilient pads circumscribing said central shank portions at each arcuately spaced mounting means location, and adapted to be confined within each said bore, said resilient pads having a body with a solid volume less than said bore and being adapted to peRmit limited relative arcuate motion between said driver hub and said ring gear in response to torque loading.
 2. The centrifugal pump means as defined in claim 1 being particularly characterized in that said bores are formed within said driver hub and a threaded bore is formed within said ring gear, and wherein shoulder bolts with smooth central shank portions couple said ring gear to said driver hub.
 3. The centrifugal pump means as defined in claim 1 being particularly characterized in that said arcuately spaced mounting means are disposed at 90*intervals adjacent the periphery of said ring gear and driver hub.
 4. The centrifugal pump means as defined in claim 1 being particularly characterized in that said resilient pads are formed of rubber having a hardness ranging from between about 60 durometer and 80 durometer.
 5. The centrifugal pump means as defined in claim 1 being particularly characterized in that said resilient pads have a generally triangular configuration with a finite thickness and with a central bore extending therethrough, and with laterally converging sides extending from said bore.
 6. The centrifugal pump means as defined in claim 5 being particularly characterized in that said resilient pads are fabricated from rubber and have a hardness ranging from between about 60 durometer and 80 durometer.
 7. The centrifugal pump means as defined in claim 1 being particularly characterized in that said pinion gear is secured to said drive shaft along two flats formed along said shaft and arranged in oppositely disposed relationship thereon, the flats comprising approximately 50 percent of the total periphery of said drive shaft.
 8. In combination: a centrifugal pump means having an enclosed pumping chamber with an inlet and an outlet, an impeller journaled for rotation within said chamber and a drive shaft arranged to provide rotational energy to said impeller; and a power transmission means coupled to said centrifugal pump means for driving said drive shaft, said power-transmission means being mounted within a housing and having an input arranged for coupling to a source of rotational energy with the rotational energy being coupled to said drive shaft; a. said power transmission means comprising a ring and pinion gear system with driver hub means secured to said input coupling, said ring and pinion gear system including: b. a ring gear means with axially inwardly directed teeth secured to said driver hub and arranged for limited relative arcuate rotation with said driver hub within said power transmission housing, said driver hub including an outwardly extending flange having an annular recess extending radially inwardly from the outer edge thereof to form a guiding shoulder for said ring gear, said ring gear means having a plurality of radially outwardly disposed equally arcuately spaced mounting means thereon for coupling to said driver hub and having an inwardly extending flange with an inner edge mating with said guiding shoulder; c. a plurality of radially outwardly disposed equally arcuately spaced mounting means formed in said driver hub for accommodating coupling of said ring gear mounting means to said driver hub; d. a pinion gear in mesh with said axially inwardly directed teeth and fast on said drive shaft, said pinion gear being fabricated from a material less durable than said ring gear and being sacrificial; e. a plurality of bores and a plurality of coupling members having central shank portions and being disposed at each arcuately spaced mounting means location; and f. a resilient means disposed at each arcuately spaced mounting means location, and adapted to be confined within each said bore, said resilient means being adapted to forcibly accommodate limited relative shifting between said driver hub and said ring gear in response to torque loading. 